The present invention relates to devices for traveling in snow or water, and, more particularly, to un-powered devices for traveling down snow-covered slopes or behind boats.
Where possible, e.g., in the northern latitudes, humans have long exploited the recreational possibilities of winter. Frozen ponds mean ice fishing, hockey, and ice skating. Snow covered trails mean snowmobiling and cross-country skiing. And snow covered slopes mean downhill skiing, snowboarding, tubing, and sledding. In fact, formal facilities (e.g., groomed slopes, chair lifts) for the latter have become so numerous in recent years that the opportunities for conveniently and inexpensively engaging in downhill winter sports have increased to unprecedented levels.
Unfortunately, however, many people either cannot or do not take part in downhill winter sports. This is because the sports oftentimes require expensive equipment, a high degree of skill, or both, and can be quite dangerous. Rental equipment may ease the bother of the former, but the latter two always remain a problem. Skiing, for example, can take years to learn well, and there are all too many unfortunate examples of fatal or debilitating accidents on the slopes.
Accordingly, many alternatives to the more skill-oriented and dangerous downhill winter sports have been proposed over the years. These have primarily taken the form of small, xe2x80x9cgravity poweredxe2x80x9d vehicles such as sleds and inflated tubes. In particular, the latter have become quite popular at ski resorts, and basically mirror the idea of the simple sled: a person, sitting or lying on a tube, slides down a snow-covered hill in a straight path and in a more-or-less uncontrolled manner. Tubing is fun and economical, but suffers from a lack of directional control that makes it rather unappealing for those seeking a more xe2x80x9cinteractive,xe2x80x9d skiing-like experience. Additionally, this lack of control causes problems at resorts or other ski facilities. For example, tube runs must be properly groomed to ensure that people traveling downhill on the tubes go in the right direction, and resort personnel must be stationed at the top of the run to ensure that only one person goes down at a time (because the people using the tubes have no control and can only travel, more-or-less, in a straight line downhill).
Recognizing these problems, many xe2x80x9csteerablexe2x80x9d sleds have been proposed over the years. For example, U.S. Pat. No. 3,366,395 to Bjork (xe2x80x9cBjorkxe2x80x9d) shows a three-runner sled whose single front runner can be turned via a pair of handlebars, and U.S. Design Pat. No. 316,234 to Mirisch, Sr. (xe2x80x9cMirisch, Sr.xe2x80x9d) shows a tray-like sled having a front steering member operated by a person""s feet. Although these designs are theoretically functional, they demonstrate why steerable sleds have never really caught on in the marketplace. More specifically, many sleds simply do not work that well in varied snow conditions. For example, sleds with deep, blade-like runners, like the one in Bjork, are almost useless in loose powder conditions. Likewise, tray-like sleds, like the one in Mirisch, Sr., are only useful on packed slopes or trails. Additionally, even if these steerable sleds function in certain snow conditions, they rarely, if ever, provide an optimum, ski-like level of control. Typically, a user can only change the sled""s general direction of travel, cannot make hard left or right turns, and has no effective means for braking. Further, many sleds can be heavy or awkward, making them impractical for use at ski facilities with chair lifts.
Accordingly, a primary object of the present invention is to provide an un-powered ski vehicle that operates well and is highly maneuverable in most snow conditions.
Another primary object of the present invention is to provide an un-powered ski vehicle that is compatible with chair lifts.
An additional primary object of the present invention is to provide an un-powered ski vehicle that has an effective braking mechanism.
An inflatable tube ski vehicle with steering mechanism comprises an air-inflated, torus-shaped tube or bladder and a ski insert positioned in the bladder""s central opening. The ski insert can be dish-shaped, in which case it is attached to the underside of the bladder by way of straps or other mechanical fasteners. Alternatively, the ski insert can be contoured to partially wrap around the top and bottom of the bladder, like a tire rim, such that the ski insert is effectively attached to the bladder by way of an air lock seal. In either case, the ski vehicle is provided with a steering/braking mechanism comprising left and right, generally L-shaped lever arms pivotally attached to the ski insert near their midpoints. The lever arms pass through left and right side slots or openings provided in the ski insert, such that upper portions of the lever arms lie generally above the top of the ski insert, while lower portions of the lever arms lie below the top of the ski insert. Handles are attached to upper ends of the lever arms, while snow rakes, shaped for engaging snow, are attached to lower ends of the lever arms. The lever arms can be moved from a retracted position, wherein the snow rakes lie generally tucked up into the side slots, and to a deployed position, wherein the snow rakes extend significantly beyond the bottom of the ski insert for engaging snow. Also, two parallel runners are attached to the bottom of the ski insert.
To use the ski vehicle, a rider sits in the ski insert and draped over the bladder, with the rider""s legs extending over the front of the vehicle. In this position, the rider can grasp the handles and travel downhill. With the lever arms in their retracted position, the snow rakes do not interfere with passing snow, and the vehicle travels straight downhill, as facilitated by the runners. To turn left or right, the rider simply pulls on the left or right lever arm, respectively, causing the applicable snow rake to extend down into the snow. To brake, both arms are pulled simultaneously. The harder the rider pulls on either lever arm alone (for steering), or both lever arms together (for braking), the more aggressively the vehicle turns or slows down, as applicable. Because the ski vehicle is round and the weight of the vehicle and rider are largely uniformly distributed over the center of the vehicle, and because the lever arms extend down through the central opening of the bladder, a pivot or fulcrum point occurs directly under the rider""s seat, allowing the ski vehicle to make relatively tight turns.